Urban Infra Revolution - Towards sustainable and innovative construction

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URBAN INFRA REVOLUTION TOWARDS SUSTAINABLE AND INNOVATIVE CONSTRUCTION


The project team.

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CONTENTS Creating a cleaner tomorrow today About the environmental impacts of

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geopolymer composites

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From laboratory to industrial scale

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Characterization and pre-treatment of industrial side streams

Construction industry materials from waste Potential of geopolymer composites – quality,

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environmental friendliness and 3D printing

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Printer development and product printing

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Sustainable geopolymer business

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From material to a construction product

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Adventures inside a city model

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Success beyond expectations

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CREATING A CLEANER TOMORROW TODAY Modern urban infrastructure is mainly made with steel-reinforced concretebased materials. They contain high volumes of energy and virgin materials and produce high levels of CO2 emissions. In the Lappeenranta region alone carbon dioxide emissions from cement production amount to approximately 340,000 tonnes/CO2e/year.

Author: Eeva Pihlajaniemi, City of Lappeenranta

The Urban Infra Revolution (UIR) project saw the City of Lappeenranta, LUT University and local businesses working together to develop new building components by replacing cement with materials made from the side streams and construction waste of local industry. The goal was to replace current concretereinforcement materials with fibres and use 3D printing to produce a sustainable (low-carbon) and cost-­effective material that provides new aesthetic possibilities and a manufacturing process that enables innovative construction.

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Current production methods are slow and labour-intensive, and not conducive to innovative product designs. The project team developed a new method that can be used to produce a concrete-like geopolymer composite material, and thus promote sustainable construction. It paves the way for versatile, aesthetically pleasing and innovative urban planning solutions that also increase the safety and well-being of residents. However, existing 3D printing technology­has not been able to meet the needs of Finland’s construction­industry and harsh climate. The innovative geopolymer composite materials developed in the course of the project have particular appeal to operators who are looking for new circular economy alternatives to conventional raw materials. Landfills are filling up with not just demolition waste but also many other materials that could be used to produce geopolymer composites, such as tailings, green liquor dregs, and ash from the forest industry and power plants.


THE URBAN INFRA REVOLUTION (UIR) PROJECT HAD FOUR MAIN GOALS:

1.

Advocating revolutionary urban design

The project sought to increase interaction between city authorities, residents and designers as well as material R&D experts and developers of new manufacturing technologies (3D printing). Sophisticated production techniques and geopolymer composites make it possible to design and build revolutionary urban structures that improve safety and wellbeing by promoting multifunctionality, aesthetics and innovative use of space.

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Promoting sustainable urban construction

The goal was to combine the environmental, economic, social and cultural aspects of urban construction. The project team set out to develop a closed-loop material cycle as well as faster, safer and more versatile industrial methods that are also environmentally friendly.

3.

Creating a circular economy of local urban construction businesses

The project team wanted to develop a circular economy by creating new business models based on local cooperation. The aim was to promote the technological advancement of local businesses of all sizes, focusing in particular on the scalability and transferability of urban construction technologies. New recyclable products and technologies that meet industry standards have significant industrial potential in global markets as well.

4.

Helping society to adapt to and mitigate climate change

The project team was looking for comprehensive low-carbon solutions based on low-emission raw materials and production processes for various stages of the supply chain: raw material sourcing and production, printer installation and assembly, product printing and transport. Happy reading!

CONSTRUCTION REVOLUTION PILOTING BUSINESS MODELS LUT University

SUSTAINABILITY ASSESSMENT LUT University Apila Group

METHODOLOGY DEVELOPMENT Fimatec LUT University

PRODUCT DESIGN AND VIRTUAL MODELLING LAB University Of Applied Sciences Total Design Design Reform

MATERIAL DEVELOPMENT LUT University Apila Group Outotec

RECYCLED RAW MATERIALS UPM Metsä Group Nordkalk Stora Enso

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ABOUT THE ENVIRONMENTAL IMPACTS OF GEOPOLYMER COMPOSITES

Authors: Jutta Nuortila-Jokinen, Mariam Abdulkareem, Jouni Havukainen, LUT University

Cement is the key binding material in concrete production, and its unique properties as regard to availability, usability, price, etc. make it highly in demand with an estimated 4.2 billion tonnes of global production in 2019. Because of this, cement contributes 4­–8% of global CO2 emissions causing a huge environmental burden. This is why the cement industry is actively seeking more sustainable lower carbon solutions. The use of geopolymer-based materials in concrete applications could significantly reduce CO2 emissions thanks to the low carbon footprint of raw materials with a high concentration of silica and alumina from which they can be prepared, e.g. industrial side streams or waste such as fly ash. However, the environmental impact of geopolymer composites (GPC) is highly dependent on the raw materials used. In the UIR project, the geopolymer composite development was based on high extent use of secondary raw materials, i.e. industrial side streams. Such side streams include, among others, fly ash from the pulp and paper industry and power plants, slag

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OUTPUTS: Environmental performance analysis of geocomposite products Summary of environmental performance results

from the steel industry and mining industry tailings.

methods to be used in the recipe development work.

In addition to the secondary raw materials themselves, the processing of the raw materials, product manufacturing and the logistics connected to the whole value chain of the product influence the environmental impact of the final product. This is why life cycle assessments (LCA) and sustainability evaluations were carried out all through the project to support product and process development.

Secondary raw materials such as industrial side streams are seldom ready to use and thus require extra processing, such as crushing and sieving, prior to use. However, the environmental impact of this processing is usually much lower than the extraction or manufacturing of the virgin raw materials. Additive manufacturing, which is more commonly known as 3D printing, carries several environmental benefits compared to traditional casting technology. It uses less material due to effective design, reduces waste, such as construction waste of formwork, and minimizes inefficiencies during the building process. Additive manufacturing also enables the use of internal reinforcements, such as various kinds of natural and mineral fibres, instead of ordinary steel reinforcements, which improves the recyclability of the material. All these features increase the durability of geopolymer composites and decrease the environmental impact of the construction process.

Environmental impacts depend on the recipes used.

Geopolymer composites are not de facto more environmentally benign than conventional concrete as the impact is highly dependent on the recipe. In fact, the environmental impact varied between +40% and -98% depending on the quality and quantity of the raw materials used in the geopolymer composites compared to conventional concrete. It was found that sodium silicate, the commonly used alkali activator, was the main contributor to the environmental impact of the GPC, which is why it was essential to find alternative activators or activating


C5 GP

Oth ers

GP C4

Binding material

rs he Ot B maindin ter g ial Act ivat or

Co nv co tion ennc al re te

GPC3

rs

h Ot

WATER

150 100

0

The composition of the five geopolymer composite recipes (GPC 1 to 5) and conventional concrete as a reference.

CEMENT BINDER

200

50

s er

Binding l materia Activator

Ot he

Others

Bind mat ing eria l Ac tiv ato r

C2 GP

nt

e

m Ce

300 250

GPC1

Others

350

ing l nd ia Bi ter a m

FINE AND COARSE AGGREGATES e.g. sand and gravel

Betoni

GPC1

GPC2

GPC3

GPC4

GPC5

Global warming potential (GWP) results of geopolymer concretes in comparison to conventional concrete. The environmental impact varied between +40% and -98% depending on the quality and quantity of the raw materials used in the geopolymer composites compared to conventional concrete.

ALKALI ACTIVATOR

e.g. sodium silicate, sodium hydroxide

BINDING MATERIAL e.g. metakaolin, fly ash, slag

FINE AND COARSE AGGREGATES e.g. sand and gravel

GEOPOLYMER COMPOSITE

CONCRETE

The general composition of conventional concrete and alkali-activated geopolymers.

Life cycle assessment (LCA) is used to calculate the potential environmental impacts related to all the life-cycle phases of the product under investigation. This so-called cradle-to-grave approach covers all the phases starting from raw material extraction and production, through manufacturing and transport, and ultimately end-of-life treatment. The potential environmental impacts consist of the material and energy inputs and outputs that are

passing though the studied system boundary during the lifetime of the product. LCA results can provide information on possible hotspots in the production systems, meaning the life-cycle phases or processes that are causing a significant contribution to the environmental impacts. This information can then be utilized to evaluate which changes in product systems could be effective and cost-effective to reduce the environmental impacts.

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FROM LABORATORY TO INDUSTRIAL SCALE

Authors: Janne Kauppi, Vladimir Zhukov, Metso Outotec

Millions of tonnes of tailings with no commercial use are produced every year in Europe. Instead, tailings are typically used in various earthworks applications, such as to backfill mines and as a covering material for surface landfills. Geocomposite materials are technological innovations that have particular appeal in industrial sectors where sustainable development is important. Products made using geopolymer technology represent future product families and are characterized by cheap local raw material, high structural integrity, low carbon footprint and multiple uses in the same location. The novelty of the material also increases its potential as part of the design of tomorrow’s built environments; it brings new dimensions to the readiness to use free design, advanced manufacturing automation and robotics.

INNOVATIVE CONSTRUCTION MATERIAL WITH ECOLOGICAL AND ECONOMIC POTENTIAL The UIR project succeeded in identifying commercial opportunities related to tailings, which can be enriched in this context by means of geopolymer chemistry. In the future,

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tailings could completely replace natural sand as the fine aggregate used in construction-grade geopolymer materials. Unused tailings have excellent potential in reducing CO2 emissions compared to existing building materials. The mineralogy of each mining concession is different, and each operator therefore needs to develop a recipe that works for them. Research has also shown that some mineralogical systems require very few commercial chemicals and are therefore highly competitive and environmentally friendly compared to, for example, steel-reinforced concrete. New kinds of industrially designed instrument systems have promising potential for 3D printing, eliminating sharp edges, creating optimal geometry for industrial processes and providing excellent compressive strength and earthquake resistance. 3D printing achieves these properties at a lower overall cost compared to steel structures and Portland steel-cement concrete foundations. However, it should be noted that geocomposite printing is still in its infancy and the scale is small for industrial applications. Industry’s need for large-scale

structural models capable of convincing decision-makers must also be taken into account. From the industry perspective, it appears that geopolymers and manufacturing based on 3D printing have a brighter future in the mining sector than even in the construction industry. It is very important to correctly understand the roles of research and product development in the process of ramping additive manufacturing up to an innovative industrial scale. Geocomposites are extremely well placed to break through in miningrelated construction.

UIR AS A VEHICLE OF VERSATILE INNOVATION AND BUSINESS DEVELOPMENT Metso Outotec was involved in the project since its inception. Cooperation with LUT University and other partners enabled the implementation of a well-run development project of a high standard.


FUTURE STRATEGY BASED ON MORE SUSTAINABLE DEVELOPMENT

A similar jump can also be made in terms of the processing plant itself. In the future, it may be possible to print entire plants from tailings.

From an environmental and economic perspective, industrial tailings-based mining products have a clear edge over steel: most of the materials are already within the mining concession and 3D printing has now been proven to be both a possible and an affordable manufacturing technique.

The goal set for the project was to design a unique urban product made from a new material, which could be used to build new and attractive living environments and to familiarize the public with the material and the project. The project involved, for example, building a noise

barrier near Pontus School in Lappeenranta, which is designed to look organic and multidimensional compared to solutions based on conventional casting technology. Products made using a similar technology can also be found in the city centres of Lappeenranta and Imatra, where various kinds of benches and planters have been printed for residents to enjoy.

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Authors: Antti Häkkinen, Teemu Kinnarinen, Mehmet Kucuk, LUT University

CHARACTERIZATION AND PRE-TREATMENT OF INDUSTRIAL SIDE STREAMS AT THE FOUNTAINS OF SIDE STREAMS

LOCAL PRODUCERS PREFERRED

There are tens of industrial side streams available in South Karelia; local companies produce a vast variety of ashes, precipitates, sludges, tailings, metal slags and construction wastes. ­Finnish forest industry has traditionally operated actively in Southeast Finland. It produces large amounts of bioashes, sludges and green liquor dregs and therefore the availability of industrial side streams in the area is good. However, only a small fraction of these side streams has been studied as potential raw materials for new kinds of substances.

The majority of possible raw materials for geopolymer composites were acquired from industry located close to Lappeenranta. The most important sources were biomass boilers, chemical recovery cycles of pulp mills and a local mine that produces large amounts of tailings. After the pre-screening phase, 23 different side streams were selected for more detailed investigations, and 18 of these side streams originated in Southeast Finland. Local production is one of the key aspects in sustainable recycling, because the environmental impacts of transporting raw materials should never exceed the advantages obtained by recycling.

For this reason, we did not have existing paths to follow arising from previous studies and it was necessary for us to start our project by learning to understand the properties of the side streams to be able to reliably predict their suitability as potential raw materials of new innovative composites.

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‘Local’ is a key word for sustainable recycling.

FROM RESULTS TO PRODUCTION The main objective of the characteri-

zation of side streams was to discover what are the different elements and compounds in the side streams and what are their most important physical characteristics. By utilizing the modern selection of analytical equipment at LUT University, it was possible to determine characteristics such as chemical composition, particle size and shape, specific surface area, solubility and heat resistance. In addition to this, numerous close-up images were obtained from the samples using a scanning electron microscope. Some examples of these images are presented in Figure 1. When enough information is collected about the basic building blocks of the geopolymer composites, it is possible to use this information during the actual material development phase as a guideline for making valid decisions. The results from the characterization phase can be considered as a kind of database that enables the producer of the final products to search the background information and then make the adjustments required.


PRE-TREATMENT MAKES THE IMPOSSIBLE POSSIBLE Successful utilization of industrial side streams is often challenging. How many companies have really taken the trouble of building their industrial premises by using some other materials than reinforced concrete? Or how many construction companies have had the courage to try alternative materials for apartment buildings, etc.? They are almost non-existing. It is obvious that only few side streams are suitable as such to be used in geopolymer composites that could replace traditional con-

crete mixtures. The main reason for this is that the properties of the side streams often vary with time, the side streams may have too fine or too coarse a particle size, and they also might be too reactive or too passive. Fortunately, these heterogeneous materials can be modified by applying several fairly simple mechanical methods such as crushing, milling, screening and classification according to differences between particle densities or sizes. The objective of pre-treatment in some cases might be to remove some unwanted components whereas in some other applications they are used for con-

Precipitation / Gelation Pulp & paper industry

Summary report of pre-treatment and activation Summary report of laboratory test results Mechanical activation grinding unit

12M, 40°C

10 000

8 000

10 000

FA1-Al

FA1-Si

FA2-Al

FA2-Si

6

9

12

NaOH (M)

15

0 20

FA2-Al FA2-Si

4 000

2 000

3

FA1-Si

6 000

4 000

4 000

FA1-Al

8 000

FA2-Al

6 000

FA2-Si

6 000

0

FA1-Al

FA1-Si

2 000

Biomass fly ash

Summary report of characterization

12M, 3h (FA1), 6h (FA2)

Al, Si (mg/L)

Dissolution

OUTPUTS:

60 °C, 3h (FA1), 6h (FA2)

8 000 NaOH

centrating the target components. Sometimes it is enough to just change the particle size distribution of the material to make the impossible possible.

2 000

30

40

50

Temperature (°C)

60

0

0

2

4

Time (hours)

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Examples of the dissolution of aluminium and silicon in two industrial fly-ash samples under different conditions.

A

B

C

D

Examples of side streams studied under a scanning electron microscope; a) fly ash, b) bottom ash, c) tailings, d) construction waste

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RECIPE 1

6 % 37 % 39 %

18 %

6 % 35 %

Water Tailings Bottom ash Geopolymer binders, incl. metakaolin and liquid glass

13 % 13 %

Water Tailings Bottom ash Steel slag Geopolymer binders, incl. coal fly ash, calcium aluminate cement and liquid glass

RECIPE 5

4 % 29 % 44 % 23,1 %

Water Tailings Bottom ash Geopolymer binders, incl. metakaolin, blast-furnace slag and liquid glass

37 %

37 % 30 %

40 %

21 %

30

6

MPa

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Water Tailings Bottom ash Geopolymer binders, incl. coal fly ash, calcium-aluminate cement and liquid glass

Water Tailings Bark-boiler fly ash Geopolymer binders, incl. coal fly ash and sodium hydroxide

RECIPE 0

12 %

40

0

17 %

27 %

RECIPE 4

17 %

10

20

17 %

50

10

Water Tailings Bottom ash Cement

4 2

Recipe 1

Recipe 2

Recipe 3

Recipe 4

Recipe 5

Recipe 0

COMPRESSIVE STRENGTH BASED ON STANDARD TESTS (28 DAYS)

10

45 %

RECIPE 3

32 %

MPa

RECIPE 2

5 %

0

Recipe 1

Recipe 2

Recipe 3

Recipe 4

Recipe 5

Recipe 0

28-DAY FLEXURAL STRENGTH


CONSTRUCTION INDUSTRY MATERIALS FROM WASTE The ultimate responsibility for the development of the new material fell on Apila Group. Work on the recipes began in January 2018, and the goal was a material with a circular economy material content of more than 95%. Apila’s starting point was the 23 different side streams analysed by LUT University. A review of relevant literature revealed that fly ash and mining industry side streams had also been used in similar geopolymer applications previously, but it took a chemical analysis to identify the 23 side streams that could potentially be used.

In order to progress faster to the 3D printing stage, Apila decided to base its first recipes on commercial metakaolin as the binding material and use local side streams as fillers and aggregates. The first recipe (Recipe 1) was published in the summer of 2018, and it already had a side stream content of 68%. The goal of recipe development was to create a strong, rheologically fluid mass that remained

1

2

DISCOVERY OF THE WINNING FORMULA For its next experiments, Apila used commercial binding materials made from side streams instead of meta­ kaolin. A total of six recipes could be finalized based on numerous material tests and more formal standardized object tests (cubes and prisms), which were found to be suitable for materials in various applications. Recipe 2 had a circular economy material content of 91%, and it hardened quickly in moulds and was also suitable for 3D printing based on continuous mixing and feeding. Recipe 3 had a circular economy material content of 95%, it was strong and fast to harden, and had potential in the construction industry. Recipe 5 was a compromise that combined

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4

the industrial reliability of Recipe 1 and low carbon­footprint, having a circular economy material content of 82%. Recipe 0 was a benchmark based on Portland cement that had a circular economy material content of 69%. Recipe 4 proved to be the winning­­­ formula: a just-add-water mixture with a circular economy material content of 99.6%. The material is 3D-printable and suitable for low-consumption applications.

PERFORMANCE All the materials created were subjected to standard construction industry tests. Tests designed to establish how materials react to different industrial or weather conditions were also performed. The tests showed that geopolymer composites can, at their best, match the performance of similar construction industry products in terms of flexural strength and durability. On the other hand, the fact that geopolymer composites harden so quickly gives them a huge advantage and exciting characteristics from the perspective of a range of applications.

5

0

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Authors: Mervi Matilainen, Juha Timonen and Olli Mulari, photos: Eetu Pietarinen, Apila Group

FASTER, BETTER

workable for a sufficiently long period of time. It also had to harden quickly when subjected to heat to enable 3D printing. Once these characteristics were achieved, it was possible to move on to the development of a laboratory/city-scale 3D printer.


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POTENTIAL OF GEO­ POLYMER COMPOSITES

– QUALITY, ENVIRONMENTAL FRIENDLINESS AND 3D PRINTING Geopolymer technology provides a good starting point for curbing climate change­and reducing CO2 emissions from the construction industry thanks to the ability of geopolymers to act as an alternative to the industry’s most commonly used binding material, Portland cement. The strength of the geopolymer composite developed in the course of the UIR project lies in the use of waste materials, which promotes sustainability and reduces energy consumption compared to the same volume of Portland-cement production. Tangible environmental impacts can be eliminated by using organic and inorganic waste materials in the cement industry to change characteristics and even as fillers. A range of different source materials containing high levels of silicon dioxide and aluminium can be used for geopolymer synthesis.

The aim of the UIR project was to respond to the need to find an environmentally friendly way to build in the future. LUT University contrib-

PROVEN VERSATILITY AND DURABILITY The temperature and speed at which a material hardens and the direction and duration of its compressive

strength are key factors in determining the strength of 3D-printed powder-based geopolymers. The structural and mechanical characteristics of geopolymers and their excellent chemical and fire-resistance properties make them a good raw material for 3D printing. A computer-based scaling exercise suggested that the original material costs of geopolymer composites were approximately 32% higher than those of conventional concrete of the same grade (M45). Geopolymer development can lead to beneficial characteristics, such as durability, reduced use of natural resources, lower maintenance costs and better mechanical properties. The composition of costs was studied with respect to both on-site and factory-based 3D printing of geopolymers. Time, costs and quality were taken into account, as these factors correlate positively with cost. The cost of 3D printing a house on site was also estimated to be lower than that of conventional factory-based printing.

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Author: Timo Kärki, LUT University

THE ROLE OF ‘LOCAL’ IN BUILDING A SUSTAINABLE FUTURE

uted to the project by conducting research to ensure the quality of the new material. LUT University studied five types of raw materials produced as side streams in different industrial sectors in South Karelia and the potential of using these raw materials commercially for the 3D printing of geopolymers at construction sites and in factory conditions. The initial investment needed for transporting, storing and pre-treating these raw materials was also studied. Raw material transport was explored from the perspective of two main functions: logistics and transport management. Cost analyses were produced focusing on suppliers as well as strategic and operative functions. The annual investment needed for each raw material’s pre-treatment technology was also described in the reports. Parameters were determined for the geopolymer synthesis and strength requirements for the different types of geopolymers.


PRINTER DEVELOPMENT AND PRODUCT PRINTING OUTPUTS:

3D printer for a geopolymer composite

Advances in printer technology have also made industrial-scale 3D printing of conventional concrete and concrete-like materials a more common and viable alternative, although universal printing standards are yet to be adopted.

Author: Tuomas Hallikas, Fimatec Finnish Intelligent Module Apartments

3D printing provides a pathway to economically and ecologically sustainable construction featuring versatile, elaborate designs. The new concrete-like material developed in the course of the UIR project also needed its own printer.

STRONG PRINTING KNOW-HOW IN SOUTH KARELIA The role of Imatra-based Fimatec Oy was to develop a 3D printer that can ultimately be used to print the new concrete-like material on a large, industrial scale. The printer development process consisted of a number of steps, starting with early versions that were based on a robotic arm. The first versions were capable of running small-scale material tests using a geopolymer composite.

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The development work during the project increased understanding about the properties and further development of geopolymer composites that need to be taken into account in printer production. For example, water plays an important role in forming the structure of geopolymers, which is why ways to control its volume need to be explored as part of the printer development process in order to optimize flow characteristics. The printing media also need to be mixed for a specific period of time to achieve the required chemical reaction. Finally, development efforts need to take into account the flow of materials and various printer settings, such as temperature and layer thickness as well as the number of modules that can be printed at a time.

BRIGHT FUTURE AHEAD FOR GEOPOLYMER COMPOSITES 3D printing enables a wide range of near-organic designs, which Fimatec developed in collaboration with design experts from Design Reform. The final development version of the printer was capable of producing

new kinds of urban products, such as noise barriers, benches, planters and skate park structures. The pilot products are modular, and the same module can be used in different products that can be placed in various kinds of environments and used in different ways. The finished products were placed around Lappeenranta and Imatra for local residents to admire and enjoy. Geopolymer composites are challenging to print with current 3D printer technology due to issues with the performance and uniformity of the material. 3D printing technology suitable for printing geopolymer composites still needs to be developed further before it can be used for industrial-scale serial production. It is nevertheless worth noting that geopolymer composites appear to be easier to produce by means of 3D printing than concrete. It has been estimated that 3D printing will be deployed on a large scale in the construction industry within 5 to 10 years.


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Authors: Jutta Nuortila-Jokinen, Annastiina Rintala, Evgeniya Tsytsyna, LUT University

SUSTAINABLE GEOPOLYMER BUSINESS There are various factors that are critical for creating business: the availability of suitable raw materials, product characteristics and applications, the market’s products and competing products, the most potential end products, the structure of the potential business ecosystem and possible business models, and the life-cycle costs of the end products relative to competing products. The companies worldwide currently running business based on geopolymer composites were benchmarked for their products and business models at LUT University. Geopolymer-based concrete is utilized relatively little in construction at the moment because 1. current material standards hinder the acceptance of geopolymer technology; 2. the availability of industrial side streams varies by location, and so do the their volumes and qualities; and 3. the cost of geopolymer production easily exceeds that of ordinary Portland cement (OPC) production. The most common side streams that are used in geopolymer composites are blast furnace slag and coal fly ash, which are also used as supplementary cementitious materials in OPC concrete, and the current utilization rate of these side streams is generally high. Many slags/ashes that can be, and currently are, used for soil stabili-

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zation purposes in earthworks and in fertilization can serve as aggregates in concrete making. This can create significant competition in the secondary raw material market, and the availability of local secondary raw material sources can become a bottleneck for GPC production. Moreover, the coal fly ash that was found to be better suited for GPC production than biobased fly ash is a disappearing resource in Europe. The most common drivers for any industry to adopt new materials are the cost efficiency and/or superior performance of the material. Materials based on secondary raw materials – such as geopolymer composites – are usually more expensive than those made of virgin materials. In this case, when an alkali activator was used in GPC it was found to be the determinant to the cost of geopolymer composite and the overall cost was estimated to be significantly higher compared to that of conventional concrete. Thus, as the price competition is not in favour of geopolymer composites, they must beat the competing materials in their environmental and/or technical performance in order to attract market demand. It is noteworthy that legislation can, through various means, also guide companies to use secondary

raw materials to promote circular economy, so that the price of a material or product no longer determines the generation of demand.

THE POTENTIAL OF GEOPOLYMERS LIES IN THEIR PROPERTIES AND ECO-FRIENDLINESS The strengths of geopolymer composites include, among others, fire and water resistance, corrosion resistance of chemicals, acids and salts, insulation properties, flexural tensile strength and very fast curing time compared to concrete. In addition, as geo­polymer­composites are at their best low carbon and 3D-printable, this creates an attractive combination of properties to industry, which are particularly well suited to various solutions in e.g. the construction and process industries. For example, process tanks in different shapes with optimum flow properties can be printed from geopolymer composites because steel reinforcements limiting the shape in casting are not required. In addition, production is fast, labour and production costs are lower than in casting, and the printing process is resource-efficient and sustainable. However, it is important to find new usable side streams, as well as new applications where geopolymer composites provide added value that no other material can.

OUTPUTS: Market potential report Description of a viable, sustainable business ecosystem Report of the acceptance procedure


FROM MATERIAL TO A CONSTRUCTION PRODUCT In order to access the markets in the EU, construction products must comply with extensive standards and regulations set for the products. EU regulation is set to improve the free movement of construction products in the EU by laying down uniform rules for the marketing of these products and by providing a systematic way to assess the performance of construction products. In this way legislation and product standardization also work as a baseline for industries to verify the safety of novel geopolymer materials and products.

barriers, for example, need to comply with common European product standards. When entering the markets, a product must meet the requirements set in the EN 14388:2015 standard and, applicable national and local instructions must also be observed. The Finnish Transport Infrastructure Agency has issued its own guidance on noise barriers along motorways and railways in Finland. Product characteristics required of all noise barriers relate to, for example, sound absorption performance as well as resistance to loads and forest fire.

A product’s applicability for use in construction must always be assessed case by case based on its intended use, local conditions and the requirements laid down in the particular construction regulations. Commercial manufacturers of noise

PRODUCTS MADE FROM GEOPOLYMER COMPOSITES REQUIRE TYPE APPROVAL

Other potential slags/ Blast furnace slag / coal fly ash ashes

While the intended use, local conditions and product regulations set the requirements for the actual end

Certain fractions of consumer waste

BINDER PRECURSORS

Certain ashes / other

Construction

As many of the geopolymer composite material properties are comparable to concrete, the standardized tests for concrete and the associated product standardization framework were used as a reference. The primary properties of concrete are resistance to compression and flexion. Depending on the end product, additional performance requirements are set for the material; in flooring tiles, for example, a certain level of resistance to abrasion must be achieved. This project involved establishing a general protocol for meeting the safety-related, environmental and mechanical requirements of construction products. This document is intended to help companies to seek approval for commercial geopolymer composite products in the future.

Mining tailings / side rock

ALKALI ACTIVATORS

GP COMPOSITE MAKING

product, specific requirements for the material used in the product manufacturing must also be met. Geopolymer composites are a new material not yet covered by EU construction product standards. Therefore, an applicable reference to indicate the conformity of the material properties was needed.

Slag/ash

REINFORCEMENTS

AGGREGATES

Demolition

Earthworks

Fertilization

The material flows of geopolymer composite production and the current state of side stream utilization. indicates points where material processing currently exists. points to processes where processing does not yet exist or is done only on a pilot scale and that therefore need new operators in the GPC business ecosystem.

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Authors: Terhi Jantunen, Matti Kettunen, Mikko Holm, City of Lappeenranta and Mauri Huttunen, Timo Lehtoviita, LAB University of Applied Sciences

ADVENTURES INSIDE A CITY MODEL As the old saying goes, a picture is worth a thousand words. The claim may seem exaggerated, but it provides an interesting reference point and inspires thoughts of what it would be like to step into a picture and move around in it. The adage also answers the question of what would be the best way to present the results of a project that created revolutionary technologies that solve future challenges and can be used to build sustainable, high-quality living environments based on a completely new design language. The City of Lappeenranta joined forces with LAB University of Applied Sciences and Design Reform to build two city models: a browser-based one and one based on a video game engine. Both are efficient interactive tools that provide a technically accurate and visually impressive overview that professionals can use in urban planning and residents can access to get involved in designing their living environment. The city models were designed and built taking into account the scalability and potential uses of the information and materials produced during

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the course of the project as well as the possibility of also benefiting from the outputs of the project in the future. Requirements were agreed for accuracy, quality and information content beforehand based on the project’s objectives in order to produce enough source data. The high standard of the source data enabled the use of a range of modelling­software and the creation of the kind of accurate and visually striking city model that the project sought for different environments. The browser-based city model is easily accessible to the public and allows them to browse and comment on various kinds of plans. The model was built using an application called MAPGETS, developed by FCG Oy for the visualization of three-dimensional data. Local residents were able to use the browser-based model to give feedback on current urban planning initiatives and to explore the project team’s visions for the centre of Lappeenranta in 2030 and 2050. The project also gave local residents the opportunity to add content. The model features ideas submitted to the New City Products competition

as well as urban structures designed by students of Pontus School. A separate Virtual Reality Expo was built in the Venla meeting room of Lappeenranta City Hall, where the public can explore a virtual city on a grander scale. It is based on Unreal Engine video game technology and features a large, high-resolution LED wall and a sophisticated sound system that together transport visitors to a realistic virtual environment depicting the centre of Lappeenranta. The content developed for the game engine model can also be used flexibly in other environments, such as virtual reality headsets and three-dimensional CAVE (Cave Automatic Virtual Environment) solutions. Going forward, the environment in the City Hall can be incorporated into various kinds of urban planning workshops, meetings, lectures and press conferences.

OUTPUTS: Virtual Reality Expo


Virtual city model based on a video game engine.

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SUCCESS BEYOND EXPECTATIONS TARGETS MET IN MANY RESPECTS

This was a hugely ambitious project, and there is reason to be proud of the results. Eight different performance indicators were chosen for the project even before the application was submitted. The indicators, and how well the project succeeded relative to the indicators, are discussed in more detail below.

1.

The project team wanted to develop a 100% recyclable concrete-like circular economy material for the construction industry based on a geopolymer composite with a circular economy material content of more than 95%. The project exceeded expectations in this respect. Recipe 4 proved to be the winning formula with a circular economy material content of 99.6%. The material is fully recyclable and printable.

Author: Eeva Pihlajaniemi, City of Lappeenranta

2.

The goal was to limit virgin side streams to less than 5% and achieve a circular economy material content of more than 95%. The virgin material content of the new geopolymer composite material­developed in the course of the project can be as low as 0.4% and its circular economy material content as high as 99.6%. These are great achievements. We consider Recipe 4 our winning formula. Recipe 3 also hit the target with a circular economy material content of 95%.

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3.

The project team sought to create technologically advanced new materials capable of withstanding the extreme weather conditions of northern climates by comparing especially the physical and chemical performance of the materials against the requirements of product standards (e.g. strength, flexibility, thaw resistance of water-based and anti-freeze solutions, water absorption and extractability). All the materials created were subjected to standard construction industry tests. Tests designed to establish how materials react to different industrial or weather conditions were also performed. The tests showed that geopolymer composites can, at their best, match the performance of similar construction industry products in terms of flexural strength and durability. On the other hand, the fact that geopolymer composites harden so quickly gives them a huge advantage and exciting characteristics from the perspective of a range of applications.

4.

The team wanted to design revolutionary, aesthetically pleasing and safe multifunctional structures that could solve real-life urban planning challenges, for example, by featuring shapes that have better soundproofing properties than similar products. Most of the feedback on design collected from the public (more than 75%, which was the target) was positive and encouraging. New designs make a city more attractive. The effectiveness of the noise barrier could not be tested in practice during the project. Testing the barrier’s soundproofing properties in laboratory conditions would have required a large number of printed modules, which was not possible within the timescale.

5.

The ambitious goal at the beginning of the project was to get the authorities to sign off on the methods and criteria of type approval, which is required for the CE marking of the pilot products. There


is no internationally harmonized standardization system (“CE marking method”) for the material itself at the moment, but this does not prevent the use of geopolymers in urban construction. There are no restrictions on material with respect to, for example, noise barriers and skate park structures. Breaking through to the market and pursuing business are nevertheless more difficult, albeit not impossible, as a result. Type approval takes time, and the project team ultimately decided to just lay down the criteria and the protocol but not actually seek type approval for the pilot products.

6.

Circular economy-based new and sophisticated business models have the potential to create, either directly or indirectly, between 50 and 200 new jobs in local

industry. The project team explored five different business models. Creating jobs based on the new business models is a goal to be pursued over several years. When the final report was published, it was still too early to say whether the project succeeded in this respect. The new material developed during the course of the project combined with 3D printing is a novel solution, and spreading the message and commercializing the solution will take time. Experts estimate that this could take as long as between five and eight years.

7.

Global market potential is particularly important when the domestic market is relatively small. One of the solutions piloted during the course of the project was a 3D-printed noise barrier for railways. Global market potential was not explored, but the project team estimated that approximately 25% of the noise barriers supplied to Finnish railways annually could be produced using three or four printers.

8.

The project team set out to look for comprehensive solutions with a low carbon footprint using low-emission raw materials and production technologies at various stages of the supply chain. One specific target was for the new geopolymer composite material to produce 90% less CO2 emissions

from the use of cement (0% cement) compared to concrete. The target was exceeded, and it is safe to say that a new potential construction material was born. The industrial side streams used in the recipes were sourced locally, with the exception of coal fly ash, which was used in a few recipes and transported from a production facility of a commercial operator in Hausjärvi approximately 200 km away. The goal was to limit the transport distance of raw materials to 100 km for local industrial side streams. The availability, volume and quality of the side streams used to make the material vary depending on location, and their test–retest reliability is therefore not easily scalable. The recipes need to be fine-tuned for each application. It is clear that circular business models are here to stay. The business processes included in the models are designed to recycle resources infinitely, minimizing the use of virgin raw materials and carbon footprint. However, businesses will only adopt new materials if the new materials offer a competitive advantage over the materials they already use. This needs to be given particular attention during a potential follow-up project, which is being brainstormed at the moment.

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LOWER CARBON FOOTPRINT WITH LOCALLY PRODUCED CIRCULAR ECONOMY MATERIALS

3D PRINTING

REVOLUTION

SUSTAINABLE

BUSINESS

GROUNDBREAKING

CONCRETE-LIKE MATERIAL

URBAN INFRA REVOLUTION  100% RECYCLABLE

AESTHETICALLY PLEASING DESIGN LANGUAGE

EUROPEAN UNION

European Regional Development Fund

SAFER AND HAPPIER RESIDENTS ENJOYING FRESH URBAN DESIGNS